perpsective

I am curious how it's supposed to look like on screen. I created a sector with three markers the first is at 0,0,0 I call "center", the second is at -208.64, 133.66, 74.98 I call "test" and the third is at -277.1, 0, -277.1 I call "m01". When I look at all 3 with the center of screen is on "center" it appears that "test" is to the left of "m01 or further from center" but shouldn't "m01" appear to the left of "test" and further from center since the X coordinate of "test" is lower than "m01" However I did notice that if I change the X of "m01" from -277.1 to -477.1 then it appears as if "m01" is to left of "test". Is this just a matter of I just need to adjust the perspective or am I failing to understand how XYZ are seen, or something else entirely. Also for clarity when I first bring up a sector what is the default perspective am I seeing (X,Y), (X,Z), or (Y,Z) I would appreciate any help, thanks.